In the Military there is a long standing tradition that you do not march soldiers over a bridge in step. When marching and approaching a bridge the command of Route Step, MARCH is given. This command keeps the soldiers marching in formation, but every soldier is allowed to march at her/his own step. Although this is widely practiced in the Army, I found very few who knew the reason why.

What could have possibly prompted this tradition?

(In reply to re: Simple ... by Hugo)

What every-one has said so far seams to be correct, but, if you look at the recent problems with "The Millenium Bridge" in London, the answer may not be so straight forward.

".....The research indicated the the movement was caused by the sideways loads we generate when walking. Chance correlation of our footsteps when we walk in a crowd generated slight sideways movement of the bridge. It then becomes more comfortable for people to walk in synchronisation with the bridge movement....."

So to clarify, even if the soldiers were to cross a bridge walking out of step, eventually, if the bridge has a natural resonance of about 1.3Hz (the time between most peoples steps) and it does start to "vibrate" then the soldiers will fall into step.

We may need to find another solution.

see "http://www.arup.com/milleniumbridge/challenge" for more details.

Posted by Juggler on 2005-04-17 09:40:09